JPH10221133A - Electrode structure for electromagnetic flowmeter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode structure, for an electromagnetic flowmeter, which is assembled easily and whose costs are low. SOLUTION: An electrode 21a which comprises a flange part 211 at its upper end is inserted, from the outside, into an electrode insertion hole 16 having a formed lining 15 which is pasted internally on the inner wall of a pipe part 11 at a measuring pipe and on a part of an electrode seat 13 and which is composed of a corrosion-resistant insulating material. A diaphragm 222 as a pressure means is arranged on the surface of the flange part 211 via an insulating member 28 which is used to insulate the electrode 21a electrically from the electrode seat 13. A cap screw 25a is screwed to the electrode seat 13 so as to press the diaphragm 222. The flange part 211 is pressed to the seal face of the lining 15. The seal face which can resist a change with the passage of time is formed. The insulating member 28 may be arranged between the diaphragm 222 and the cap screw 25a. The diaphragm 222 can be replaced with a leaf spring. The cap screw 25a can be formed of an insulating material so as to eliminate the insulating member 28.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic flow meter for measuring a flow rate of a conductive fluid flowing in a measuring tube.

[0002]

2. Description of the Related Art Electromagnetic flowmeters are based on Faraday's theory that when a conductive fluid flows across a magnetic field, an electromotive force proportional to its flow velocity is induced in a direction orthogonal to the direction of the flow and the direction of the magnetic field. It measures the volume flow rate of a fluid using the law of electromagnetic induction. Usually, as shown in FIG.
A measurement pipe connected to the pipe 2 and used for flowing a measurement fluid, a pair of electromagnets for generating a magnetic field, a pair of electrodes for measuring the induced electromotive force, and the electromotive force thereof. It is configured with a converter unit 40 that performs arithmetic processing of electric power and performs display and the like.

FIG. 6 shows a main part of a conventionally known electromagnetic flow meter, in which (a) is a side view as viewed from a direction perpendicular to a flow path, and an upper half shows a cross section. . (B)
FIG. 3 is a cross-sectional view in a direction orthogonal to the flow channel. The measurement pipe 10 has a cylindrical pipe portion 11 through which a measurement fluid flows, and a pipe 2.
And a pair of electrode seats 13 for attaching electrodes to the center of the pipe 11. An electrode portion 20 as shown in FIG. A pair of electromagnets 30 are disposed facing the outside of the pipe portion 11 at a position rotated 90 degrees from the electrode seat 13, and the electromagnets 30 generate a magnetic field orthogonal to the flow path inside the pipe portion 11. .

Here, the configuration of the conventional electrode section will be described with reference to FIG. A lining 15 made of a corrosion-resistant insulating material such as, for example, fluorine resin is lined on the inner wall of the pipe portion 11 of the measuring tube 10 and a part of the electrode seat 13. An electrode 21 having a flange 211 at an intermediate portion is inserted from the outside into an electrode insertion hole 16 formed at a portion corresponding to the electrode seat 13 of the lining 15, and a disc spring 221 and a washer are provided on the flange 211. 23 and an insulating ring 24 are overlapped with each other so as to pass through the upper part of the electrode 21. In this state, when the holding screw 25 is further screwed into the electrode seat 13, the disc spring 221 is pressed via the insulating ring 24 and the washer 23, and the flange portion 211 of the electrode 21 and the lining 15 are brought into close contact with each other. The electrode 21 seals the electrode insertion hole 16.

As described above, the conventional electrode structure has a complicated structure and a large number of parts, so that the assembling work is not easy and the cost is high.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and to provide an electrode structure of an electromagnetic flowmeter which is easy to assemble and inexpensive.

[0007]

According to a first aspect of the present invention, there is provided a measuring tube having a lined lining through which a conductive measuring fluid is flown, and an electrode seat provided on the measuring tube. An electrode that is inserted from the outside of the tube to extract an electromotive force corresponding to the flow rate of the measurement fluid, and a flange provided on the electrode on a sealing surface of the lining material provided at the opening of the electrode seat with an appropriate pressure. In an electrode structure of an electromagnetic flowmeter that forms a sealed state that can withstand the aging of the sealing surface by pressing, an electrode having a flange at one end and a flange of the electrode on the sealing surface of the lining material with an appropriate pressure. A pressing means, a set screw screwed into the electrode seat to seal the electrode and the electrode seat by pressing the pressing means, and inserted between the electrode flange and the set screw. And an insulating member for electrically insulating the electrode and the electrode seat.

By providing an electrode having a flange at one end, the upper surface of the electrode becomes flat, and the electrode can be electrically insulated from the electrode seat by a plate-like insulating member. In the second invention, a measuring pipe having a lined lining through which a conductive measuring fluid flows, and a flow rate of the measuring fluid inserted into an electrode seat provided on the measuring pipe from outside the measuring pipe. An electrode for extracting a corresponding electromotive force, and can withstand a temporal change of the sealing surface by pressing a flange portion provided on the electrode with an appropriate pressure against a sealing surface of the lining material provided in the opening of the electrode seat. In an electrode structure of an electromagnetic flowmeter that forms a sealed state, an electrode having a flange portion at one end, a means for pressing the flange portion of the electrode against the sealing surface of the lining material with an appropriate pressure, and being screwed into the electrode seat and pressed There is provided a cap screw made of an insulating material for sealing the electrode and the electrode seat by pressing the means and electrically insulating the electrode and the electrode seat.

Since the cap screw is formed of an insulating material, a member for electrically insulating the electrode from the electrode seat is not required. Also, a diaphragm or a leaf spring is used as the pressing means. These are very simple in structure and easy to manufacture.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to examples. Parts having the same functions and structures as those of the prior art are denoted by the same reference numerals. [First Embodiment] FIG. 1 is a sectional view showing a first embodiment of an electrode structure of an electromagnetic flowmeter according to the present invention. Lined on the inner wall of the pipe part 11 of the measuring tube and a part of the electrode seat 13,
For example, an electrode 21a having a flange 211 at the upper end is inserted from the outside into an electrode insertion hole 16 formed in a lining 15 made of a corrosion-resistant insulating material such as fluorine resin. On the upper surface of the flange portion 211 of the electrode 21a, a diaphragm 222 as a pressing means is disposed via an insulating member 28 for electrically insulating the electrode 21a from the electrode seat 13.
When the cap screw 25a is screwed into the electrode seat 13, the diaphragm 222 is pressed, and the flange portion 21 of the electrode 21a is pressed.
1 is pressed against the sealing surface of the lining 15 to form a sealing surface that can withstand aging. In addition, the insulating member
The upper surface of 28 has a recess for positioning diaphragm 222.

In the embodiment of FIG. 1, the diaphragm 222 is shown as the pressing means, but a leaf spring is also effective. These can be easily manufactured by, for example, pressing a stainless steel plate. FIG. 2 shows these shapes, (a) is a plan view of the diaphragm 222,
(B) is a sectional view of the diaphragm 222, and (c) is a leaf spring 22.
FIG. 3D is a plan view, and FIG. 3D is a sectional view of the leaf spring 223.

The signal line 27 is drawn from a side surface of the flange 211 through a hole formed in a side surface of the electrode seat 13. In the above embodiment, the insulating member 28 is disposed between the flange portion 211 and the diaphragm 222.
The arrangement between the diaphragm 222 and the cap screw 25a is also effective. In this case, it is necessary to form a recess or the like for positioning the diaphragm 222 on the upper surface of the flange portion 211.

As apparent from a comparison between FIG. 4 showing the electrode structure of the prior art and FIG. 1 showing the electrode structure of this embodiment,
In this embodiment, the structure of the parts is simplified and the number of parts is reduced, so that the assembling work is facilitated and the parts cost is reduced. [Second Embodiment] FIG. 3 is a sectional view showing a second embodiment of the electrode structure of the electromagnetic flowmeter according to the present invention. The difference from the first embodiment is that the cap screw 25a is a cap screw 25b made of an insulating material such as ceramic, and the insulating member 28 is not used. In this case, when the diaphragm 222 as the pressing means contacts the electrode seat 13, the electrode 21b and the electrode seat
Since the electrical insulation between them cannot be maintained, a recess for positioning the diaphragm 222 is formed on the upper surface of the flange portion 211, and the diaphragm 222 is positioned here. Other structures are the same as those of the first embodiment.

In this embodiment, the number of parts is further reduced as compared with the first embodiment, so that the assembling work is further facilitated and the parts cost is further reduced. In the above embodiment, the pressing means such as the diaphragm 222 is positioned by providing a recess in the flange 211, but the pressing means can be easily positioned by providing a projection at the center of the flange 211. it can. For example, if a recess is provided at the center of the diaphragm 222 and the recess is arranged in the opposite direction to that of FIG. In this case, set screw 25a or 25b
May be a flat surface.

[0015]

According to the first aspect of the present invention, a measuring tube having a lined lining through which a conductive measuring fluid is flown, and an electrode seat provided on the measuring tube is provided outside the measuring tube. And an electrode for extracting an electromotive force corresponding to the flow rate of the measurement fluid by being inserted from the electrode, and pressing a flange portion provided on the electrode against a sealing surface of the lining material provided at the opening of the electrode seat with an appropriate pressure. In the electrode structure of the electromagnetic flowmeter, which forms a sealed state that can withstand the aging of the sealing surface, means for pressing the flange portion of the electrode against the sealing surface of the lining material with an appropriate pressure by using an electrode having a flange at one end. And a presser screw that is screwed into the electrode seat to press the pressing means to seal the electrode and the electrode seat, and that the electrode and the electrode seat are inserted between the electrode flange portion and the presser screw. Since a plate-shaped insulating member for gaseous insulation is provided, the upper surface of the electrode is flattened, and the plate-shaped insulating member can electrically insulate the electrode from the electrode seat. And the cost of parts is reduced.

According to the second aspect of the present invention, the measuring tube having a lined lining through which the conductive measuring fluid flows, and the measuring tube inserted into the electrode seat provided on the measuring tube from the outside of the measuring tube. An electrode for taking out an electromotive force corresponding to the flow velocity of the fluid, and the sealing surface of the lining material provided in the opening of the electrode seat is pressed against the flange portion provided on the electrode with an appropriate pressure, whereby the aging of the sealing surface is performed. In an electrode structure of an electromagnetic flowmeter that forms a sealed state that can withstand changes, an electrode having a flange at one end, a means for pressing the flange of the electrode against the sealing surface of the lining material with an appropriate pressure, and an electrode seat. Since the electrode and the electrode seat are sealed by screwing and pressing the pressing means, and a cap screw made of an insulating material for electrically insulating the electrode and the electrode seat, the electrode and the electrode seat are provided. Electrically separate member for insulating is unnecessary to Gokuza, assembly work becomes easier,
The number of parts is further reduced, and the cost of parts is further reduced.

Further, as the pressing means, an inexpensive diaphragm or leaf spring having a simple structure can be used, so that the cost of parts is further reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of an electrode structure of an electromagnetic flowmeter according to the present invention.

FIG. 2 shows an embodiment of a pressing means used in the electrode structure of the electromagnetic flowmeter according to the present invention, wherein (a) and (b) are a plan view and a sectional view of a diaphragm, and (c) and (d) are leaf springs. Plan view and cross-sectional view

FIG. 3 is a sectional view showing the structure of a second embodiment of the electrode structure of the electromagnetic flow meter according to the present invention.

FIG. 4 is a sectional view showing an electrode structure of a conventional electromagnetic flowmeter.

FIG. 5 is a perspective view showing an installation state example of an electromagnetic flowmeter.

6A and 6B show a main part of the electromagnetic flow meter, wherein FIG. 6A is a side view as viewed from a direction perpendicular to the flow path, and FIG. 6B is a cross-sectional view in a direction perpendicular to the flow path.

[Explanation of symbols]

 1 Electromagnetic flowmeter 2 Piping 10 Measuring tube 11 Pipe portion of measuring tube 12 Side plate 13 Electrode seat 14 Welding joint 15 Lining 16 Electrode insertion hole 20, 20a, 20b Electrode 21, 21a, 21b Electrode 211 Flange 221 Disc spring 222 Diaphragm 223 Leaf spring 23, 26 Washer 24 Insulation ring 27 Signal wire 25, 25a, 25b Holding screw 28 Insulation member 30 Electromagnet 40 Transducer part

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Tatsuji every floor 1-1-1, Tanabe-Nitta, Kawasaki-ku, Kawasaki-shi, Kanagawa Fuji Electric Co., Ltd.

Claims (3)

[Claims] 1. A measuring tube having a lined lining through which a conductive measuring fluid flows, and inserted into an electrode seat provided on the measuring tube from the outside of the measuring tube to correspond to the flow rate of the measuring fluid. An electrode for extracting an electromotive force, and a sealing state capable of withstanding a temporal change of the sealing surface by pressing a flange portion provided on the electrode with an appropriate pressure against a sealing surface of a lining material provided at an opening of the electrode seat. In the electrode structure of the electromagnetic flowmeter, an electrode having a flange portion at one end, a means for pressing the flange portion of the electrode at an appropriate pressure on the sealing surface of the lining material, and a pressing means screwed into the electrode seat are provided. A presser screw for sealing the electrode and the electrode seat by pressing, and an insulating member inserted between the flange portion of the electrode and the presser screw to electrically insulate the electrode and the electrode seat. Electrode structure of an electromagnetic flowmeter, characterized in that it comprises. 2. A measuring tube having a lined lining through which a conductive measuring fluid flows, and inserted into an electrode seat provided on the measuring tube from the outside of the measuring tube to correspond to the flow rate of the measuring fluid. An electrode for extracting an electromotive force, and a sealing state capable of withstanding a temporal change of the sealing surface by pressing a flange portion provided on the electrode with an appropriate pressure against a sealing surface of a lining material provided at an opening of the electrode seat. In the electrode structure of the electromagnetic flowmeter, an electrode having a flange portion at one end, a means for pressing the flange portion of the electrode at an appropriate pressure on the sealing surface of the lining material, and a pressing means screwed into the electrode seat are provided. An electrode for an electromagnetic flowmeter, comprising: a cap screw made of an insulating material for sealing the electrode and the electrode seat by pressing, and electrically insulating the electrode and the electrode seat. Elephants. 3. An electrode structure for an electromagnetic flow meter according to claim 1, wherein said pressing means is a diaphragm or a leaf spring.